Altering cold-regulated gene expression decouples the salicylic acid-growth trade-off in Arabidopsis.

In Arabidopsis (Arabidopsis thaliana), overproduction of salicylic acid (SA) increases disease resistance and abiotic stress tolerance but penalizes growth. This growth-defense trade-off has hindered the adoption of SA-based disease management strategies in agriculture. However, investigation of how SA inhibits plant growth has been challenging because many SA-hyperaccumulating Arabidopsis mutants have developmental defects due to the pleiotropic effects of the underlying genes. Here, we heterologously expressed a bacterial SA synthase gene in Arabidopsis and observed that elevated SA levels decreased plant growth and reduced the expression of cold-regulated (COR) genes in a dose-dependent manner. Growth suppression was exacerbated at below-ambient temperatures. Severing the SA-responsiveness of individual COR genes was sufficient to overcome the growth inhibition caused by elevated SA at ambient and below-ambient temperatures while preserving disease- and abiotic-stress-related benefits. Our results show the potential of decoupling SA-mediated growth and defense trade-offs for improving crop productivity.

Fitting electron density as a physically sound basis for the development of interatomic potentials of complex alloys.

The development of new interatomic potentials to model metallic systems is a difficult task, due in part to the dependence between the parameters that describe the electron density and the short-range interactions. Parameter search methods are prone to false convergence. To solve this problem, we have developed a methodology for obtaining the electron density parameters independently of the short-range interactions, so that physically sound parameters can be obtained to describe the electron density, after which the short-range parameters can be fitted, thus reducing the complexity of the process and yielding better interatomic potentials. With the new method we can develop self-consistent, accurate force fields, using solely calculations, without the need to fit to experimental data. Density functional theory calculations are used to compute the observables with which the potential is fit. We applied the method to a Ni-based Inconel 625 superalloy (IN625), modelled here as Ni, Cr, Mo and Fe solid solution alloys. The capability of the force fields developed using this new method is validated, by comparing the structural and thermo-elastic properties predicted with the force fields, with the corresponding experimental data, both for single crystals and polycrystalline alloys.

Thermostructural behaviour of Ni-Cr materials: modelling of bulk and nanoparticle systems.

The thermostructural properties of Ni-Cr materials, as bulk and nanoparticle (NP) systems, have been predicted with a newly developed interatomic potential, for Ni/Cr ratios from 100/0 to 60/40. The potential, which has been fitted using experimental data and further validated using Density Functional Theory (DFT), describes correctly the variation with temperature of lattice parameters and the coefficient of thermal expansion, from 100 K to 1000 K. Using this potential, we have performed Molecular Dynamics (MD) simulations on bulk Ni-Cr alloys of various compositions, for which no experimental data are available. Similarly, NPs with diameters of 3, 5, 7, and 10 nm were studied. We found a very rapid convergence of NP properties with the size of the systems, showing already the 5 nm NPs with a thermostructural behaviour similar to the bulk. MD simulations of two 5 nm NPs show very little sintering and thermally induced damage, for temperatures between 300 K and 1000 K, suggesting that materials formed by agglomeration of Ni-Cr NPs meet the thermostructural stability requirements for catalysis applications.

Effect of Hemp Extraction Procedures on Cannabinoid and Terpenoid Composition.

A variety of techniques have been developed to extract hemp phytochemicals for research and consumption. Some of the most common processes in the industry include supercritical CO2 extraction, hydrodistillation, and solvent-based (ethanol) extractions. Each of these processes has the potential to differentially extract various phytochemicals, which would impact their efficacy, tolerability, and safety. However, despite these differences, there has been no direct comparison of the methods and the resulting phytochemical composition. This work aimed to compare cannabinoid and terpene profiles using the three primary commercial procedures, using hemp inflorescence from a CBD/CBG dominant Cannabis sativa L. cultivar. Extracts were then evaluated for their terpene and cannabinoid content using GC-MS and LC-MS/MS, respectively. Hydrodistilled extracts contained the most variety and abundance of terpenes with ß-caryophyllene to be the most concentrated terpene (25-42 mg/g). Supercritical CO2 extracts displayed a minimal variety of terpenes, but the most variety and abundance of cannabinoids with CBD ranging from 12.8-20.6 mg/g. Ethanol extracts contained the most acidic cannabinoids with 3.2-4.1 mg/g of CBDA along with minor terpene levels. The resulting extracts demonstrated substantially different chemical profiles and highlight how the process used to extract hemp can play a large role in product composition and potential biological effects.

Paracetamol degradation pathways in soil after biochar addition.

Little is known about the effect of biochar on the degradation of paracetamol in soil, considering the ubiquity of this pollutant in the environment. Given the importance of the electrochemical properties of biochar for contaminant remediation, we investigated the influence of raw and designer redox-active biochars on paracetamol degradation in soil. Metabolite quantification indicated that a minimum of 53% of the spiked paracetamol was transformed in biochar-amended soil, resulting in the accumulation of different degradation products. The identification of these products allowed us to chart paracetamol degradation pathways in soil with and without biochar amendment. Some of the major degradation routes were observed to proceed via catechol and phenol, despite being previously described as having only a minor role in paracetamol metabolism. Additionally, a new transformation route from paracetamol to NAPQI was discovered in anaerobic soil originating from direct redox reactions on the surface of the designer biochars. These results may contribute to change our understanding of the environmental fate of paracetamol in soil and the role of biochar in its biodegradation.

Secondary Terpenes in Cannabis sativa L.: Synthesis and Synergy.

Cannabis is a complex biosynthetic plant, with a long history of medicinal use. While cannabinoids have received the majority of the attention for their psychoactive and pharmacological activities, cannabis produces a diverse array of phytochemicals, such as terpenes. These compounds are known to play a role in the aroma and flavor of cannabis but are potent biologically active molecules that exert effects on infectious as well as chronic diseases. Furthermore, terpenes have the potential to play important roles, such as synergistic and/or entourage compounds that modulate the activity of the cannabinoids. This review highlights the diversity and bioactivities of terpenes in cannabis, especially minor or secondary terpenes that are less concentrated in cannabis on a by-mass basis. We also explore the question of the entourage effect in cannabis, which studies to date have supported or refuted the concept of synergy in cannabis, and where synergy experimentation is headed, to better understand the interplay between phytochemicals within Cannabis sativa L.

Overcoming biochar limitations to remediate pentachlorophenol in soil by modifying its electrochemical properties.

In this study, we produced modified biochars with enhanced electrochemical properties to increase PCP remediation in soil. Although all biochars enhanced PCP remediation in aerobic conditions, only a few did in anaerobic soil. The most successful modifications were (i) the preloading of biomass with 10% w/w FeCl3, to obtain a biochar rich in redox-active metals (B-Fe); (ii) the oxidation of a conductive biochar pyrolyzed at 1000 ºC with 0.025 M KMnO4, to produce a biochar with both moderate conductivity and redox capacity (B-1000-KMnO4); and (iii) KMnO4 oxidation of an amorphous biochar pyrolyzed at 400 ºC to obtain a biochar with very high redox capacity (B-KMnO4). B-Fe reduced extractable PCP to almost zero after 50 days in both incubations, but showed slow kinetics of remediation in aerobic soil. B-1000-KMnO4 had the highest rate of remediation under aerobic conditions, but no significant effect under anaerobic conditions. B-KMnO4, however, presented high rates of remediation and high removal of extractable PCP under both conditions, which made it the recommended modification strategy for increased PCP remediation. We found that the degree of remediation primarily depends on the redox capacity, while the rate of remediation was determined by both the conductivity and redox capacity of biochar.

The Parasite Load of Trypanosoma cruzi Modulates Feeding and Defecation Patterns of the Chagas Disease Vector Triatoma infestans.

Trypanosoma cruzi is the causal agent of Chagas disease, a parasitic zoonosis transmitted mainly through the feces of triatomine insects. Triatoma infestans is the main triatomine vector of this disease in South America. Previous research has shown that T. cruzi infection modifies the behavior of triatomines. We evaluated, for the first time, the effect of parasite load on feeding and defecation behavior, which we quantified by using real-time PCR. The detection time of the host was shorter in infected individuals, and the number of bites increased, while the dejection time was reduced when compared with the non-infected group. A significant correlation between the parasite load and the behavioral changes registered in the infected triatomines was found. These results would indicate that the intensity of T. cruzi infection modulates the feeding and defecation behavior of T. infestans, increasing the vector competence of this triatomine vector.

Trypanosoma cruzi Parasite Load Modulates the Circadian Activity Pattern of Triatoma infestans.

American trypanosomiasis is a disease caused by the flagellate protozoan Trypanosoma cruzi, which is transmitted mainly in endemic areas by blood-sucking triatomine vectors. Triatoma infestans is the most important vector in the southern cone of South America, exhibiting a nocturnal host-seeking behavior. It has been previously documented that the parasite produces changes in some triatomine species, but this is the first time that the behavior of a vector has been evaluated in relation to its parasite load. After comparing the movement events and distance traveled of infected and non-infected T. infestans, we evaluated the change produced by different T. cruzi parasite loads on its circadian locomotor activity. We observed differences between infected and non-infected triatomines, and a significant relation between the parasite load and the increase in locomotor activity of T. infestans, which was accentuated during the photophase. This could have direct implications on the transmission of T. cruzi, as the increased movement and distance traveled could enhance the contact of the vector with the host, while increasing the predation risk for the vector, which could both constitute a risk for vectorial and oral transmission to mammals.

Numerical Analysis of Degradation and Capacity Loss in Graphite Active Particles of Li-Ion Battery Anodes.

It is well known that the performance and durability of lithium-ion batteries (LIBs) can be severely impaired by fracture events that originate in stresses due to Li ion diffusion in fast charge-discharge cycles. Existing models of battery damage overlook either the role of particle shape in stress concentration, the effect of material disorder and preexisting defects in crack initiation and propagation, or both. In this work we present a novel, three-dimensional, and coupled diffusive-mechanical numerical model that simultaneously accounts for all these phenomena by means of (i) a random particle generator and (ii) a stochastic description of material properties implemented within the lattice method framework. Our model displays the same complex fracture patterns that are found experimentally, including crack nucleation, growth, and branching. Interestingly, we show that irregularly shaped active particles can suffer mechanical damage up to 60% higher than that of otherwise equivalent spherical particles, while material defects can lead to damage increments of up to 110%. An evaluation of fracture effects in local Li-ion diffusivity shows that effective diffusion can be reduced up to 25% at the particle core due to lithiation, while it remains at ca. 5% below the undamaged value at the particle surface during delithiation. Using a simple estimate of capacity loss, we also show that the C-rate has a nonlinear effect on battery degradation, and the estimated capacity loss can surpass 10% at a 2C charging rate.

Thermomechanical Performance Analysis of Novel Cement-Based Building Envelopes with Enhanced Passive Insulation Properties.

The design of new insulating envelopes is a direct route towards energy efficient buildings. The combinations of novel materials, such as phase-change (PCM), and advanced manufacturing techniques, such as additive manufacturing, may harness important changes in the designing of building envelopes. In this work we propose a novel methodology for the design of cement-based building envelopes. Namely, we combined the use of a multiscale, multiphysical simulation framework with advanced synthesis techniques, such as the use of phase-change materials and additive manufacturing for the design of concrete envelopes with enhanced insulation properties. At the material scale, microencapsulated PCMs are added to a cementitious matrix to increase heat storage. Next, at the component level, we create novel designs for the blocks, here defined as HEXCEM, by means of additive manufacturing. The material and component design process is strongly supported on heat transfer simulations with the use of the finite element method. Effective thermal properties of the mixes can be obtained and subsequently used in macroscale simulations to account for the effect of the volume fraction of PCMs. From the experimental and numerical tests, we report an increase in the the thermal inertia, which results in thermal comfort indoors.

A Novel Physical Mechanism to Model Brownian Yet Non-Gaussian Diffusion: Theory and Application.

In the last years, a few experiments in the fields of biological and soft matter physics in colloidal suspensions have reported "normal diffusion" with a Laplacian probability distribution in the particle's displacements (i.e., Brownian yet non-Gaussian diffusion). To model this behavior, different stochastic and microscopic models have been proposed, with the former introducing new random elements that incorporate our lack of information about the media and the latter describing a limited number of interesting physical scenarios. This incentivizes the search of a more thorough understanding of how the media interacts with itself and with the particle being diffused in Brownian yet non-Gaussian diffusion. For this reason, a comprehensive mathematical model to explain Brownian yet non-Gaussian diffusion that includes weak molecular interactions is proposed in this paper. Based on the theory of interfaces by De Gennes and Langevin dynamics, it is shown that long-range interactions in a weakly interacting fluid at shorter time scales leads to a Laplacian probability distribution in the radial particle's displacements. Further, it is shown that a phase separation can explain a high diffusivity and causes this Laplacian distribution to evolve towards a Gaussian via a transition probability in the interval of time as it was observed in experiments. To verify these model predictions, the experimental data of the Brownian motion of colloidal beads on phospholipid bilayer by Wang et al. are used and compared with the results of the theory. This comparison suggests that the proposed model is able to explain qualitatively and quantitatively the Brownian yet non-Gaussian diffusion.

Three novel quantum-inspired swarm optimization algorithms using different bounded potential fields.

Based on the behavior of the quantum particles, it is possible to formulate mathematical expressions to develop metaheuristic search optimization algorithms. This paper presents three novel quantum-inspired algorithms, which scenario is a particle swarm that is excited by a Lorentz, Rosen-Morse, and Coulomb-like square root potential fields, respectively. To show the computational efficacy of the proposed optimization techniques, the paper presents a comparative study with the classical particle swarm optimization (PSO), genetic algorithm (GA), and firefly algorithm (FFA). The algorithms are used to solve 24 benchmark functions that are categorized by unimodal, multimodal, and fixed-dimension multimodal. As a finding, the algorithm inspired in the Lorentz potential field presents the most balanced computational performance in terms of exploitation (accuracy and precision), exploration (convergence speed and acceleration), and simulation time compared to the algorithms previously mentioned. A deeper analysis reveals that a strong potential field inside a well with weak asymptotic behavior leads to better exploitation and exploration attributes for unimodal, multimodal, and fixed-multimodal functions.

Computational Multiscale Solvers for Continuum Approaches.

Computational multiscale analyses are currently ubiquitous in science and technology. Different problems of interest-e.g., mechanical, fluid, thermal, or electromagnetic-involving a domain with two or more clearly distinguished spatial or temporal scales, are candidates to be solved by using this technique. Moreover, the predictable capability and potential of multiscale analysis may result in an interesting tool for the development of new concept materials, with desired macroscopic or apparent properties through the design of their microstructure, which is now even more possible with the combination of nanotechnology and additive manufacturing. Indeed, the information in terms of field variables at a finer scale is available by solving its associated localization problem. In this work, a review on the algorithmic treatment of multiscale analyses of several problems with a technological interest is presented. The paper collects both classical and modern techniques of multiscale simulation such as those based on the proper generalized decomposition (PGD) approach. Moreover, an overview of available software for the implementation of such numerical schemes is also carried out. The availability and usefulness of this technique in the design of complex microstructural systems are highlighted along the text. In this review, the fine, and hence the coarse scale, are associated with continuum variables so atomistic approaches and coarse-graining transfer techniques are out of the scope of this paper.

Mesoscale Characterization of Fracture Properties of Steel Fiber-Reinforced Concrete Using a Lattice-Particle Model.

This work presents a lattice-particle model for the analysis of steel fiber-reinforced concrete (SFRC). In this approach, fibers are explicitly modeled and connected to the concrete matrix lattice via interface elements. The interface behavior was calibrated by means of pullout tests and a range for the bond properties is proposed. The model was validated with analytical and experimental results under uniaxial tension and compression, demonstrating the ability of the model to correctly describe the effect of fiber volume fraction and distribution on fracture properties of SFRC. The lattice-particle model was integrated into a hierarchical homogenization-based scheme in which macroscopic material parameters are obtained from mesoscale simulations. Moreover, a representative volume element (RVE) analysis was carried out and the results shows that such an RVE does exist in the post-peak regime and until localization takes place. Finally, the multiscale upscaling strategy was successfully validated with three-point bending tests.

The lethality test used for estimating the potency of antivenoms against Bothrops asper snake venom: pathophysiological mechanisms, prophylactic analgesia, and a surrogate in vitro assay.

The potency of antivenoms is assessed by analyzing the neutralization of venom-induced lethality, and is expressed as the Median Effective Dose (ED50). The present study was designed to investigate the pathophysiological mechanisms responsible for lethality induced by the venom of Bothrops asper, in the experimental conditions used for the evaluation of the neutralizing potency of antivenoms. Mice injected with 4 LD50s of venom by the intraperitoneal route died within ∼25 min with drastic alterations in the abdominal organs, characterized by hemorrhage, increment in plasma extravasation, and hemoconcentration, thus leading to hypovolemia and cardiovascular collapse. Snake venom metalloproteinases (SVMPs) play a predominat role in lethality, as judged by partial inhibition by the chelating agent CaNa2EDTA. When venom was mixed with antivenom, there was a venom/antivenom ratio at which hemorrhage was significantly reduced, but mice died at later time intervals with evident hemoconcentration, indicating that other components in addition to SVMPs also contribute to plasma extravasation and lethality. Pretreatment with the analgesic tramadol did not affect the outcome of the neutralization test, thus suggesting that prophylactic (precautionary) analgesia can be introduced in this assay. Neutralization of lethality in mice correlated with neutralization of in vitro coagulant activity in human plasma.

Riesgo de resangrado y muerte en pacientes hospitalizados en el Servicio de Gastroenterología del Hospital Jesús Yerena con el diagnostico de hemorragia digestiva superior no variceal, durante el período comprendido entre enero 2002 y agosto 2008 / Rebleeding and dearth risks in inpatients at Hospital Jesús Yerena Gastoenterology Service diagnosed with non-varicose upper disgestive hemorrahage between january 2002 and august 2008

La hemorragia digestiva superior es una de las causas más frecuentes de consulta y hospitalización en los hospitales generales y en los servicios de gastroenterología a nivel mundial. Existen criterios que permiten orientarnos hacia la evolución que puedan tener estos pacientes. Los criterios de Rockall, aplicados a pacientes con hemorragia digestiva superior no variceal y según las características clínicas-endoscópicos nos permiten predecir el riesgo de resangrado y muerte. Estadificar según criterios de Rockall el riesgo de resangrado y muerte en pacientes hospitalizados con diagnostico de Hemorragia Digestiva superior no variceal a la emergencia del hospital de Lídice, durante el período comprendido entre Enero 2002 y agosto 2008. Se realiza estudio retrospectivo de corte transversal con una muestra de 150 pacientes, recopilando los datos de las historias clínicas de pacientes hospitalizados con diagnóstico de hemorragia digestiva superior no variceal a los cuales se les calculó según Rockall el riesgo de resangrado y muerte. Del total de 150 pacientes, presentaron riesgo bajo de muerte y resangrado 53 pacientes (8 resangraron y sólo 1 falleció por otra causa), riesgo intermedio 57 pacientes (14 resangraron y 2 fallecieron) y riesgo alto 40 pacientes (20 resangraron y 10 fallecieron). Nuestro trabajo confirma el valor de la escala de Rockall para determinar el riesgo de resangrado y muerte en pacientes con sangrado digestivo superior no variceal...

Upper digestive hemorrhage is one of the most frequent causes of worldwide consult and hospitalization in general hospitals and gastroenterology services as well. There are criteria allowing to being guided to the evolution that said patients could experience. Rockall criteria applied to patients with non-varicose upper digestive hemorrhage, and as per the clinical-endoscopic features, let us predict the rebleeding and death risks. According to Rockall criteria, staging the rebleeding and death risks in hospitalized patients diagnosed with non-varicose upper digestive hemorrhage at Hospital de Lidice’s ER between January 2002 and August 2008. A cross-sectioned retrospective study is carried out with a 150-patient sample, collecting clinical records data of hospitalized patients diagnosed with non-varicose upper digestive hemorrhage who were computed, according to Rockall, the rebleeding and death risks. Out of the total of 150 patients, 53 presented death and rebleeding risks (8 rebled and just 1 died due to other cause), 57 patients presented intermediate risk (14 rebled and 2 died), and patients showed high risk (20 rebled and 10 died). This research confirms the Rockall score’s value for determining the risk of rebleeding and death in patients diagnosed with non-varicose upper digestive bleeding...

Aspectos clínicos y epidemiológicos en pacientes con ERGE que acuden al Servicio de Gastroentrología del Hospital “Dr. Jesús Yerena”: enero-junio 2009 / Clinical and epidemiological aspects of gerd patients going to Hospital

La enfermedad de reflujo gastroesofágico (ERGE) es uno de los trastornos gastrointestinales con mayor prevalencia que afecta a la población en general constituyendo una de las causas frecuentes de consulta. Está relacionada con el flujo retrógrado de contenido gástrico al Esófago siendo la pirosis y la regurgitación los síntomas típicos de esta patología. Las comorbilidades, tales como Obesidad, Diabetes Mellitus, Asma, Hipertensión Arterial y Patologías de ORL se asocian con la disfunción de los mecanismos que normalmente previenen el reflujo gastroesofágico. Describir la relación existente entre los aspectos clínicos y epidemiológicos y la enfermedad de reflujo gastroesofágico en pacientes que consultan al Servicio de Gastroenterología del Hospital “Dr. Jesús Yerena”. Enero- Junio 2009. Estudio prospectivo de corte longitudinal, realizado en la población general adulta que acudió a la consulta del Servicio de Gastroenterología del Hospital General Dr. Jesús Yerena, desde Enero hasta Junio del 2009. Se utilizó una encuesta basada en criterios clínicos, epidemiológicos, de acuerdo a consensos latinoamericanos y europeos sobre ERGE. De 80 sujetos encuestados, 51 fueron femeninos y 29 masculinos. El promedio de edad fue de 52,2 años. La prevalencia de síntomas cardinales determinó que la pirosis presentó un 50,9% con respecto a la regurgitación 49%. La Hipertensión Arterial representó el 50% de las comorbilidades con respecto al resto de las mismas. Encontramos que el 25,563% consumen café, y el 28,571% ingerían alcohol al menos una vez al mes y 24,06% referían hábitos tabáquicos. Así mismo se evaluó la presencia de síntomas atípicos, describiéndose entre ellos la tos (28,03%), dolor Retroesternal (16,6%), ronquera (14,39%) y disnea (12,87%), entre otras. Nuestro estudio determinó la mayor prevalencia de ERGE en el sexo femenino, los síntomas típicos gástricos como pirosis y regurgitación no solo son predominantes también en la ERGE sino que síntomas...

The Gastroesophageal Reflux Disease (GERD) is one of the higher- prevalence gastroenterological disorders affecting the general population, placing itself as one of the most frequent causes of consult. It is related to the gastric contents’ backward flow to the esophagus; heartburn and regurgitation are the typical symptoms of this pathology. Comorbidities such as obesity, diabetes mellitus, asthma, high blood pressure, and ENT pathologies are associated with the disorder of mechanisms that regularly prevent the gastroesophageal reflux. Description of the relationship existing between the clinical and epidemiologic aspects and the gastroesophageal reflux disease on patients going to the Hospital Jesus Yerena’s Gastroenterology Service, between January and June 2009. Longitudinal section prospective study performed on a consult-attending general adult population at Hospital Jesus Yerena’s Gastroenterology Service between January and June 2009. A survey based on clinical and epidemiological criteria was used, as per Latin American and European consensus on GERD. 80 surveyed subjects: 51 female and 29 male. The average age was 52.2. The main symptoms prevalence determined that heartburn showed 50.9% regarding regurgitation that was 49%. 50% of comorbilities was represented by High Blood Pressure regarding the others. Other findings: 25.563% were coffee consumers and 28.571% were at least once a month alcohol consumers, and 24.06% were tobacco users. Likewise, the presence of atypical symptoms was assessed, and the following were described: coughing (28.03%), retrosternal pain (16.6%), hoarseness (14.39%) y dyspnea (12.87%), among others. The study determined that GERD had higher prevalence on females; that not only the typical gastric symptoms, such as heartburn and regurgitation, prevail on GERD but extraesophageal symptoms too, such as coughing, retrosternal pain and hoarseness, were ...

Dermatitis atópica: una enfermedad agobiante y de manejo problemático / Atopic dermatitis: a worrisome disease with diffcult management

L adermatitis atópica es un padecimeitno frecuente, que se asocia con asma y/o rintis alérgica. Aparece usualmente a los 2-4 meses de edad, y puede "curar" o persistir por toda la vida. El tratamiento es sintomático, y creemos que lo seguirá siendo siempre porque el órgano choque es inmodificable